Switch for refrigerating apparatus



Dec. 19, 1939. E. B. NEWILL ,2

SWITCH FOR REFRIGERATING APPARATUS Filed Sept. 28, 1937 INVENT BY WW ATTO NEYS Patented Dec. 19, 1939 UNITED STATES PATENT OFFICE SWITCH FOR REFRIGERATING APPARATUS Edward B; Newill, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application September 28, 1937, Serial No. 166,135 4 Claims. (Cl. 200-83) This inventionrelates to refrigerating appa- 20 has a removable metal cover 28 upon one side ratus and more particularly to control means for for access to a portion of the switch mechanism. refrigerating apparatus and other apparatus. The gasket 30 is provided between the metal plate Control means used for controlling different and the open face of the portion 20.

types of apparatus are usually open to the at- Within the metal portion 22 of the casing is 5 mosphere and, therefore, are subject to corroprovided a metal bellows 30 which is fastened to sion and accumulations of dirt. Furthermore, the bottom wall of the metal casing member 22 when such controls are wholly or partially open, by a thin nut 32 which is threaded onto a hollow they are subject to tampering. Any one of these stem 34 projecting from the interior of the belthree things may cause a complete or a partial lows 30. A tube 36 extends from the threaded 10 failure of the control means. portion 30 and may be employed for charging the Where the control means has no external adbellows. It is shown sealed as at 38, but may, if lustment, the problem is relatively simple since it esired, be connected'by a tube to a thermostat is usually only necessary to provide a sealed outbulbwhich may be mounted upon the cooling unit er casing. However, where an external adjustof the refrigerating system. v 15 ment need be provided, the problem of providing The bellows 30 is surrounded at the top and the seal switch means is rather diflicult. one side by a cage 40 which is fastened by rivets It is an object of my invention to provide a 42 and 44 to the bottom and end walls of the methermetically sealed control means having a sealed al casing portion 22. The upper end of the belexternal adjustment means. lows 30 is provided with a projection 45 which 20 It is another object of my invention to provide extends through the cage 40 and bears against a hermetically sealed control means with 2. diathe main lever 48 of the switch mechanism which phragm means in the sealed casing and a means is provided with an aperture 50 at one end proa'cting through the medium of said diaphragm vided with knife edges and threaded upon a demeans for adjusting the control means without pending pivot support 52 which is riveted to the 25 breaking the seal of the casing. top wall of the metal casing portion 22 by rivets Further objects and advantages of the present 54. The main lever 48 is prevented from moving invention will be apparent from the following deupwardly upon the member 52 by a shoulder upon scrlption, reference being had to the accompanythe member 52, and the main lever is supported ing drawing, wherein a preferred form of the from beneath by a cotter pin 56 which extends 30 present invention is clearly shown. through the lower portion of the member 52 be:

In the drawing: neath the main lever 48. Fig. 1 is a sectional view of one form of my The main lever 48 is provided with a molded control means taken along the line l--I of Fig. extension 58 of an insulating material provided with notches Bll at its end portion which receive 35 Fig. 2 is a sectional view taken along the line one end of a secondary lever 62 having a tension 2-2 of Fig. 1; and coil spring 64 connected to its opposite end and Fig. 3 is a perspective view of the outside of stretched to a post 68 provided upon a contact the control means. carrying lever 68 pivoted upon a pin 10 and which Briefly, I have shown a switch means provided in turn is support d y a bracket 2 xtendin 40 with a sealed casing which is adapted to be fasfrom the end wall of the casing portion 20. The

tened in heat exchange relation with the cooling contact carrying lever 88 has a downwardly exunit or in the medium to be cooled by a refrigertending contact arm 14 carrying a contact bar ating system. An external adjustment is pro- 16 at its lower end which is adapted to bridge a vided which acts through a bellows provided in pair of contacts 18 located side by side and con- 45 the casing wall to adjust the casing of the main nected through the wall of the insulating portion spring of the switch. 20 to binding screws 80 which connect the con- Referring now to the drawing, there is. shown a tacts to the electrical conductors and 84. The switch means having a box-shaped portion 20 contacts '8 limit the closing movement of the formed of a non-metallic electrical insulating contact arm 14 and the switch mechanism. The 50 material such as a phenolic condensation prodcontacts 18 are molded into the casing portion 20 uct. At one side of this casing is a metal casing so that no leakage can take place through its conportion 22 fastened to the casing 20 by screws 24 nection withthe binding screws 80.

and sealed to the casing by an asphalt or other The opening of the contact carrying lever I4 5:; suitable type of sealing means 26. The portion is controlled by a set screw 85 extending downwardly from the top wall of the insulating portion 20 for limiting the opening movement of the contact carrying lever 68 in order to control the difierential of the switch. The contact carrying lever 68 is provided with stop portions 88 and 90 above and below the secondary lever 62. The location of these stop portions determines the tripping points of the switch, and since the location of these stop portions is determined by the location of the contacts and the position of the differential screw 86, the differential of the switch may be controlled by adjusting the screw 86.

The bellows 30 is charged with a suitable volatile liquid which causes the bellows to expand and contract with changes of temperature. Where the bellows is connected to a thermostat bulb, the bellows will respond to the temperature of the thermostat bulb. Where the casing is mounted in heat exchange relation with the object or medium to be cooled or heated, as the case may be, the bellows will respond to the temperature of the metal casing 22.

The force provided by the volatile fluid within the bellows 30 is controlled by a tension coil spring 92 connected at its upper end to an ear 94 depending from the main lever 48 and connected at its lower end to a lever 96 pivoted upon a pin 98 and connected-at its other end to a bracket I02 provided with a threaded aperture which receives the threaded lower end of the stem I04. The end plate I06 of a bellows I08 is sealed to the stem I04. The upper end of the bellows I08 is sealed to the edges of an aperture I I in the walls of the metal casing portion 22. The upper portion of the stem I04 15' provided with an eye II2 which receives an eccentric I I4 provided upon the end .of a shaft II6 which is rotatably mounted in a bearing II8 provided upon the top wall of the metal casing portion 22. The opposite end of the shaft H6 is provided with an adjusting knob I20 by which the eccentric may be turned to raise or lower the stem I04 and thereby cause the lever 96 to be pivoted to stretch or contract the tension spring 92 in order to raise or lower both the cut-in and cut-out points.

In this switch, all of the connections through the walls are hermetically sealed. All of the screws are provided with gaskets, and all of the rivets are made sufiiciently tight to prevent any leakage. The differential screw may be covered with asphalt in order to make sure that no leakage will take place. The bracket I2 is mounted in the wall of the portion 20 so that no leakage will take place. The casing may be charged with air or any suitable gas. The casing may be mounted in direct heat exchange relation with the cooling unit of a refrigerating system, or a steam radiator or a fluid to be heated or cooled. By this apparatus, I have provided a sealed control means with a convenient external adjust- 'ment.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows: 1

1. A control means including a sealed casing containing a means to be operated, a pressure operated means having a movable portion within said sealed casing for operating said means to be operated, external adjustment means for said control means, and hermetically sealed means operated by said external adjustment means for adjusting the operation of said means to be operated by said pressure operated means.

2. A control means including a sealed casing containing a mechanical switch means to be opened and closed for controlling the flow of electric energy through an electric circuit, said switch means being connected to electrical conductors extending through the wall of the sealed casing, said conductors being hermetically sealed in the wall of the casing, a temperature responsive means including a mechanical operating portion within said sealed casing for opening and closing said switch means, external adjustment means for said control means, and hermetically sealed means operated by said external adjusting means for adjusting the operating portion of said temperature responsive means.

3. A control means including a sealed casing containing a switch means to be opened and closed for controlling the flow of electric energy through an electric circuit, said switch means being connected to electrical. conductors extending through the wall of the sealed casing, said conductors being hermetically sealed in the wall of the casing, a pressure operated means including a separately enclosed operating portion within.said sealed casing for opening and closing said switch means, external adjustment means for said control means, and hermetically sealed means operated by said external adjusting means for adjusting the operating portion of said pressure operated means.

4. A control means including a sealed casing, means forming a closed flexible chamber within said sealed casing, a switch means within the sealed casing operated by the expansion and contraction of the means forming the closed flexible chamber, spring means for opposing the expansion of the closed flexible chamber, external adjusting means for said control means and hermetically sealed means operated by said external adjusting means for adjusting the tension of said spring means.

EDWARD B. NEWILL.

DISCLAIMER 2,184,241.Edward B. Newill, Dayton, Ohio. SWITCH FOR REFRIGERATING APPA- RATUS. Patent dated December 19, 1939. Disclaimer filed September 20, 1940, by the assignee, General Motors Corporation.

Hereby disclaims claim 2.

[Ofiicial Gazette October 8, 1940.]

DISCLAIMER ard B. Ne'w'ill, Dayton, Ohio. SWITCH FOR REFRIGERATING APPA- 2,184,241.-Edw

RATUS. Patent dated December 19, 1939. Disclaimer filed September 20, 1940, by the assignee, General Motors Corporation.

Hereby disclaims claim 2.

[Ofiieial Gazette October 8, 1940.] 

